Allergy shots do not work on all allergies or on all people with allergies. For example, they are not used to treat
food allergies.

Allergy shots should be considered for patients with severe symptoms that are difficult to control with medications and when other forms of treatment have failed.

How Allergy Shots Work

Allergy shots decrease your sensitivity to allergens by exposing you to increasingly larger doses of the allergens to which you are reacting. An allergen is a substance that can produce an allergic, or hypersensitive response, often called an allergy attack. Pollen, dust mites, and mold spores are common allergens.

First, your doctor will use skin or blood tests to determine what you are allergic to. Then, a shot is made from small amounts of these specific allergens. With repeated shots, your body becomes less sensitive to these allergens, causing you to have a less severe allergic reaction or none at all.

It can take as long as 12 months of regular shots before you notice relief of your allergy symptoms.

Precautions While Using These Medicines

Allergy Shots Should Not Be Taken Under These Conditions:

If you are having severe
asthma
that is not controlled with medication

If you are having heart problems

If you are taking a beta-blocker

Any children under the age of 5 years

Discuss Pregnancy with Your Doctor

Women who are pregnant should not begin allergy shots. However, if a woman has been receiving allergy shots for some time when she becomes pregnant, she may be able to continue. Discuss your options with your doctor.

Discuss Other Medications

Tell your doctor if you are taking or plan to take any medications, including over-the-counter drugs, for both allergic and nonallergic conditions. Your allergy shots may affect the use of other medications.

Continue Other Measures

Allergy shots can greatly reduce allergy symptoms, but are not a guaranteed cure. Therefore, you should continue to avoid known allergens and use your medications while receiving shots.

Dosing Schedule

Allergy shots are given year-round. For the first 3-6 months, you will get 1-2 shots per week (called the build-up phase). Then, a maintenance dose is injected every few weeks to once a month. You will receive these monthly shots for 3-5 years. After this time, you may be able to stop shots completely.

Possible Side Effects

Allergy shots are usually safe. However, because they contain a small amount of an allergen, there is a risk of an adverse reaction. This may be as mild as swelling and redness at the site of the shot, which can last for 1-3 days. However, a serious, life-threatening reaction called
anaphylaxis
can occur. Such a reaction is rare.

You will receive your shot in a doctor's office, and you will be asked to wait 30 minutes after the shot before leaving. If a bad reaction occurs, the medical personnel will be able to treat you right away.

RESOURCES

American College of Asthma, Allergy, and Immunology
http://www.acaai.org

Family Doctor—American Academy of Family Physicians
http://www.familydoctor.org

CANADIAN RESOURCES

Allergy Asthma Information Association
http://aaia.ca

Health Canada
http://www.hc-sc.gc.ca

References

Allergy shots: Could they help your allergies? Family Doctor—American Academy of Family Physicians website. Available at
http://familydoctor.org/familydoctor/en/diseases-conditions/allergic-rhinitis/treatment/allergy-shots-could-they-help-your-allergies.html. Updated April 2014. Accessed December 23, 2014.

Allergy Shots: Tips to remember. American Academy of Allergy, Asthma and Immunology website. Available at:
http://www.aaaai.org/conditions-and-treatments/library/at-a-glance/allergy-shots.aspx. Accessed December 23, 2014.

Pregnancy and allergies. American College of Allergy, Asthma andImmunology website. Available at:
http://www.acaai.org/allergist/liv%5Fman/pregnancy/Pages/pregnancies-and-allergy-asthma-management.aspx. Accessed December 23, 2014.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.